| In millions, except per share items | Dec-31-22 | Dec-05-22 | Dec-31-21 | Dec-05-21 | Dec-31-20 | Dec-31-19 |
| | 10-K | 8-K | 10-K | 8-K | 10-K | 10-K |
| Revenue | 4.2 | 4.2 | 9.3 | 9.3 | 4.8 | 1.4 |
| Revenue growth | -54.8% | -54.8% | 91.3% | | 249.9% | |
| Cost of revenue | 8.4 | 8.4 | 5.8 | 5.8 | 2.7 | 0.8 |
| Gross profit (loss) | -4.3 | -4.3 | 3.4 | 3.4 | 2.1 | 0.6 |
| Gross margin | -101.5% | -101.5% | 37.0% | 37.0% | 43.4% | 41.1% |
| Research and development expenses | 109.6 | 126.8 | 74.8 | 87.5 | 20.5 | 15.4 |
| General and administrative expenses | 31.1 | 36.0 | 28.4 | 36.0 | 5.7 | 4.3 |
| Selling and marketing expenses | 7.0 | 7.0 | 4.4 | 4.4 | 1.7 | 1.0 |
| Total operating expenses | 147.7 | 317.6 | 107.6 | 235.6 | 27.8 | 20.7 |
| Operating loss | -152.0 | -152.0 | -104.2 | -104.2 | -25.7 | -20.1 |
| Operating margin | -3624.9% | -3624.9% | -1124.5% | -1124.5% | -531.5% | -1451.8% |
| Interest income | 3.7 | 3.7 | 0.4 | 0.4 | 0.2 | 0.5 |
| Other income (expense), net | 0.9 | 0.9 | 1.9 | 1.9 | 0.0 | 0.0 |
| Net loss before income taxes | -147.3 | | -101.9 | | -25.6 | -19.6 |
| Net loss | -147.3 | -147.3 | -101.9 | -101.9 | -25.6 | -19.6 |
| Unrealized loss on available-for-sale securities | -3.1 | | -0.5 | | | |
| Total comprehensive loss | -150.4 | | -102.4 | | -25.6 | -19.6 |
| |
| Net loss per share, basic | ($0.68) | ($0.68) | ($0.51) | ($0.51) | ($0.18) | ($0.17) |
| Net loss per share, diluted | ($0.68) | ($0.68) | ($0.51) | ($0.51) | ($0.18) | ($0.17) |
| |
| Weighted-average shares used in computing net loss per share, basic | 217.3 | 217.3 | 200.8 | 200.8 | 141.7 | 115.0 |
| Weighted-average shares used in computing net loss per share, diluted | 217.3 | 217.3 | 200.8 | 200.8 | 141.7 | |